Set attributes of vertices based on their age

This is a function to produce actions in response to a playwidget or Shiny input control. The mental model is that each of the vertices of some object has a certain birth time; a control sets the current time, so that vertices have ages depending on the control setting. Attributes of those vertices can then be changed.

ageControl(births, ages, objids = tagged3d(tags), tags, value = 0,
           colors = NULL, alpha = NULL, radii = NULL, vertices = NULL,
           normals = NULL, origins = NULL, texcoords = NULL,
           x = NULL, y = NULL, z = NULL,
           red = NULL, green = NULL, blue = NULL)

Arguments

births

Numeric birth times of vertices.

ages

Chosen ages at which the following attributes will apply.

objids

Object ids to which the changes apply.

tags

Alternate way to specify objids. Ignored if objids is given.

value

Initial value; typically overridden by input.

colors, alpha, radii, vertices, normals, origins, texcoords

Attributes of the vertices that can be changed. There should be one entry or row for each entry in ages.

x, y, z, red, green, blue

These one-dimensional components of vertices and colors are provided for convenience.

Details

All attributes must have the same number of entries (rows for the matrices) as the ages vector. The births vector must have the same number of entries as the number of vertices in the object.

Not all objects contain all attributes; if one is chosen that is not a property of the corresponding object, a Javascript alert() will be generated. (This restriction may be removed in the future by attempting to add the attribute when it makes sense.)

If a births entry is NA, no change will be made to that vertex.

Value

A list of class "rglControl" of cleaned up parameter values, to be used in an RGL widget.

Author

Duncan Murdoch

Examples

  saveopts <- options(rgl.useNULL = TRUE)

  theta <- seq(0, 4*pi, length.out = 100)
  xyz <- cbind(sin(theta), cos(theta), sin(theta/2))
  lineid <- plot3d(xyz, type="l", alpha = 0, lwd = 5, col = "blue")["data"]

  widget <- rglwidget() %>%
  playwidget(ageControl(births = theta,
                        ages = c(-4*pi, -4*pi, 1-4*pi, 0, 0, 1),
                        objids = lineid,
                        alpha = c(0, 1, 0, 0, 1, 0)),
             start = 0, stop = 4*pi,
             step = 0.1, rate = 4)
  if (interactive() || in_pkgdown_example())
    widget

  options(saveopts)